Herbal supplement mentioned above may be helpful if this is only mild condition.
If the condition is severe then you might have to take some medication for anxiety attack.
What causes this?
Feeling insecure financially?
Feeling insecure to maintain visa?
Feeling insecure after completing study but not getting work?
Feeling insecure about getting fired?
Feeling insecure after remaining unemployed for a longtime?
worrying too much about wife/girlfriend?
had any recent accidents?? and there are many more reason that causes this issue.
other than accident, this does not happen overnight. this is cause of something happening for a longtime. Leaving it untreated can be .... very bad. treating will give you new life.
better to consult the best physician and explain exact symptoms.
Take medication regularly and wait at least 2 to 4 weeks to see the changes in life. You may start feeling differences as soon as 2 weeks.
this happens to many people who are struggling.. you are not alone!!

Good luck and take care of yourself!!